Various thermal conduction structures have been used to dissipate heat generated by the power electronic devices of electronic circuit board assemblies. A common approach is to attach a heatsink to the circuit board substrate opposite the power electronic devices, and to incorporate thermal vias into the circuit board for thermally coupling the power devices to the heatsink. While the thermal via approach can be effectively used in certain applications, it is frequently necessary to electrically isolate the power electronic devices from the heatsink by depositing a layer of special insulating material between the circuit board and the heatsink. This not only increases the cost of the circuit board assembly, but also reduces thermal coupling of the circuit board to the heatsink. Accordingly, what is needed is a circuit board having an electrically isolated thermal conduction structure that is inexpensive to manufacture and that provides improved thermal coupling.